The cosmic 21 cm signal serves as a crucial probe for studying the evolutionary history of the Universe. However, detecting the 21 cm signal poses significant challenges due to its extremely faint nature. To mitigate the interference from the Earth’s radio frequency interference (RFI), the ground and the ionospheric effects, the Discovering the Sky at the Longest Wavelength (DSL) project will deploy a constellation of satellites in Lunar orbit, with its high-frequency daughter satellite tasked with detecting the global 21 cm signal from cosmic dawn and reionization era (CD/EoR).We intend to employ the Vari-Zeroth-Order Polynomial (VZOP) for foreground fitting and subtracting. We have studied the effect of thermal noise, thermal radiation from the Moon, the Lunar reflection, anisotropic frequency-dependent beam, inaccurate antenna beam pattern, and RFI contamination. We discovered that the RFI contamination can significantly affect the fitting process and thus prevent us from detecting the signal. Therefore, experimenting on the far side of the moon is crucial. We also discovered that using VZOP together with DSL, after 1080 orbits around the Moon, which takes about 103 days, we can successfully detect the CD/EoR 21 cm signal.

DNA barcoding approaches have been successfully applied for estimating diet composition. However, an accurate quantification in the diets of herbivores remains to be achieved. In the current study, we present a novel methodology that reveals the relationship between the actual proportions (by mass) of each herbage species in the diets and the relative proportions of the ITS2 gene sequences obtained from faecal samples to evaluate the diet composition of sheep in a meadow steppe. Nine common and twelve rare species of plants were employed for formulating six diets, along with the addition of feed supplements for improving the growth performance of sheep. Faecal samples were collected for DNA analysis over the period spanning days 7–12. A significant positive correlation (Spearman’s ρ = 0.389) was obtained between the actual proportions (by mass) of the herbage in the diet provided and the relative abundance of ITS2 sequences obtained from the faecal samples. A significant regression coefficient was found between the relative abundance of all common species and their respective herbage mass proportions. The accuracy of the relation equations, evaluated by utilizing the similarity coefficient, showed 84.69% similarity between the actual diet composition and the correct percentage. Taken together, the current study has provided empirical evidence for the accuracy and applicability of ITS2 as a DNA barcode for obtaining quantitative information about the diet composition of sheep grazing in species-rich grasslands.

Loess, a geologic record of dust, is an optimal archive for exploring paleoclimate and the paleo-dust path from source to sink. The dust path for the Songnen Plain, NE China, during the last glacial period has not been established. To address this, 63 surface sediment samples from the Northeast China Sandy Lands, i.e., Onqin Daga Sandy Land (OD), Horqin Sandy Land (HQ), Hulun Buir Sandy Land (HL), and Songnen Sandy Land (SN), and six samples from the last glacial loess in the Harbin area were collected for elemental geochemical analysis of the <10 μm fraction to quantitatively reconstruct the dust pathway using a frequentist model. The results show that these sandy lands have a distinct geochemical composition due to a control from markedly different provenances. The quantitative results indicate that the dust contribution of the southwestern SN to the Harbin loess is as high as 50.4–77.2%, followed by the OD and HQ (3.3–34.8%), the northwestern SN (0–36.8%), and the HL (0–8%). Notably, the dust contribution to the Harbin loess began to change considerably after ~46–41 ka BP, with a significant increase from 1.1% to 41.2% from the northwestern direction. Some ecological safety strategies are proposed to address dust pollution in the Harbin area.

Reducing nitrogen (N) fertilizer application is a sustainable practice in rice production. The effects of reducing N fertilizer input on grain yield and rice quality of early- and late-season dual-use rice (ELDR) in South China remain uncertain. Therefore, a short-term field trial was conducted with a high-yielding ELDR cultivar (Yuehesimiao, YHSM) and a low-yielding ELDR cultivar (Meixiangzhan 2, MXZ). The rice was cultivated with a 20% reduced N application rate (RN2), a 10% reduced rate (RN1) and the conventional N application rate (CN). In the early season, compared to CN, RN2 reduced the grain yield of YHSM and MXZ by an average of 16.1 and 6.6%, respectively, while RN1 lowered YHSM grain yield by 11.2% on average and had no effect on MXZ yield. In addition, RN2 decreased the milling and eating qualities of the two cultivars in the early season, while RN1 did not alter their milling, appearance or eating qualities. In the late season, neither RN2 nor RN1 affected grain yield or rice quality for both cultivars. Therefore, short-term reductions of 10 and 20% in N application could maintain grain yield and rice quality at current N fertilizer application rates in the late season. However, the early-season results only recommended a 10% reduced N fertilizer application rate for low-yielding ELDR cultivars to sustain grain yield and rice quality. The findings of this study can provide a theoretical basis for N management of ELDR in South China.

Palygorskite (Pal) shows great potential for physical, chemical and biological uses due to its colloidal, catalytic and adsorption properties. Pal mines, however, are facing the challenge of low-grade materials (5–15%), making it difficult to use Pal in emerging fields such as new materials, environmental protection and health. Therefore, there is an urgent need to develop an efficient method for separating and purifying Pal to obtain high purity levels. Hence, we have developed a dispersant-assisted rotating liquid film reactor separation strategy based on sodium hexametaphosphate as the dispersant. This strategy utilizes the double electron layer of Pal and the density difference between impurities to achieve effective disaggregation and purification of Pal bundles through the promotion of repulsive driving effects. Under optimal conditions, the purity of Pal can be increased from less than 10% to over 80%. This research presents a novel approach to the efficient refining of low-grade Pal. The crudely purified Pal’s adsorption capacity for methylene blue increased from 84.2 to 256.4 mg g–1.

Modern fluvial sediments provide important information about source-to-sink process and regional tectono-magmatic events in the source area, but many factors, e.g., chemical weathering, sedimentary cycles and source-rock types, can interfere with the establishment of the source-sink system. The Lalin River (LR) and the Jilin Songhua River (JSR) are two important tributaries of the Songhua River in the Songnen Plain in NE China. They have similar flow direction, topography and identical climate backgrounds, but have notably different parent-rock types in the headwater, which provides an opportunity to explore the influencing factors of river sediment composition. To this end, the point bar sediments in the two rivers were sampled for an analysis of geochemistry (including element and Sr-Nd isotopic ratios), heavy mineral and detrital zircon U-Pb dating. The results are indicative of the fact that the two rivers have the similar geochemical composition (e.g., elements and Sr isotopes) as well as chemical weathering (CIA = 51.41–57.60, CIW = 59.68–66.11, PIA = 51.95–60.23, WIP = 56.00–65.47, Rb/Sr = 0.38–0.42) and recycling (SiO2/Al2O3 = 5.79 and 5.03, ICV = 1.0 and 1.2, CIA/WIP = 0.81–1.03) characteristics, showing a major control of climate on the low-level weathering and recycling of the river sediments. However, there are significant differences in the detrital zircon U-Pb age (a significant Mesozoic age peak for the LR but an additional Precambrian peak for the JSR), Nd isotope ratio (−6.2812–8.5830 and −8.1149–10.2411 for the LR and the JSR, respectively) and to a certain extent heavy mineral composition (e.g., for the < 63 μm fraction, a dominance of hornblende and magnetite in the LR, but haematite-limonite in the JSR) in the two river sediments, indicating that source rocks largely control the composition of the river sediments. Some of the major tectono-magmatic events (e.g., crustal growth and cratonisation of the North China Craton, closure of the Paleo-Asian Ocean, subduction and rollback of the Paleo-Pacific plate) occurring in the eastern Songnen Plain are well documented in the JSR sediments but not in the LR, the difference of which is largely regulated by the source rocks in the source area.

As avionics systems become increasingly complex, traditional fault prediction methods are no longer sufficient to meet modern demands. This paper introduces four advanced fault prediction methods for avionics components, utilising a multi-step prediction strategy combined with a stacking regressor. By selecting various standard regression models as base regressors, these base regressors are first trained on the original data, and their predictions are subsequently used as input features for training a meta-regressor. Additionally, the Tree-structured Parzen Estimator (TPE) algorithm is employed for hyperparameter optimisation. The experimental results demonstrate that the proposed stacking regression methods exhibit superior accuracy in fault prediction compared to traditional single-model approaches.

A multifunctional optical diagnostic system, which includes an interferometer, a refractometer and a multi-frame shadowgraph, has been developed at the Shenguang-II upgrade laser facility to characterize underdense plasmas in experiments of the double-cone ignition scheme of inertial confinement fusion. The system employs a 266 nm laser as the probe to minimize the refraction effect and allows for flexible switching among three modes of the interferometer, refractometer and multi-frame shadowgraph. The multifunctional module comprises a pair of beam splitters that attenuate the laser, shield stray light and configure the multi-frame and interferometric modules. By adjusting the distance and angle between the beam splitters, the system can be easily adjusted and switched between the modes. Diagnostic results demonstrate that the interferometer can reconstruct electron density below 1019 cm–3, while the refractometer can diagnose density approximately up to 1020 cm–3. The multi-frame shadowgraph is used to qualitatively characterize the temporal evolution of plasmas in the cases in which the interferometer and refractometer become ineffective.

This study aimed to demonstrate the utilization value of 1PN embryos. The 1PN zygotes collected from December 2021 to September 2022 were included in this study. The embryo development, the pronuclear characteristics, and the genetic constitutions were investigated. The overall blastocyst formation and good-quality blastocyst rates in 1PN zygotes were 22.94 and 16.24%, significantly lower than those of 2PN zygotes (63.25 and 50.23%, respectively, P = 0.000). The pronuclear characteristics were found to be correlated with the developmental potential. When comparing 1PN zygotes that developed into blastocysts to those that arrested, the former exhibited a significantly larger area (749.49 ± 142.77 vs. 634.00 ± 119.05, P = 0.000), a longer diameter of pronuclear (29.81 ± 3.08 vs. 27.30 ± 3.00, P = 0.000), and a greater number of nucleolar precursor body (NPB) (11.56 ± 3.84 vs. 7.19 ± 2.73, P = 0.000). Among the tested embryos, the diploidy euploidy rate was significantly higher in blastocysts in comparison with the arrested embryos (66.67 vs. 11.76%, P = 0.000), which was also significantly higher in IVF-1PN blastocysts than in ICSI-1PN blastocysts (75.44 vs. 25.00%, P = 0.001). However, the pronuclear characteristics were not found to be linked to the chromosomal ploidy once they formed blastocysts.

In summary, while the developmental potential of 1PN zygotes is reduced, our study shows that, in addition to the reported pronuclear area and diameter, the number of NPB is also associated with their developmental potential. The 1PN blastocysts exhibit a high diploidy euploidy rate, are recommend to be clinically used post genetic testing, especially for patients who do not have other 2PN embryos available.

Compacted bentonite, used as an engineering barrier for permanent containment of high-level radioactive waste, is susceptible to mineral evolution resulting in compromise of the expected barrier performance due to alkaline–thermal chemical interaction in the near-field. To elucidate the mineral-evolution mechanisms within bentonite and the transformation of the nuclide adsorption properties during that period, experimental evolution of bentonite was conducted in a NaOH solution with a pH of 14 at temperatures ranging from 60 to 120°C. The results showed that temperature significantly affects the stability of minerals in bentonite under alkali conditions. The dissolution rate of fine-grained cristobalite in bentonite exceeds that of smectite, with the phase-transition products of smectite being temperature-dependent. As the temperature rises, smectite experiences a three-stage transformation: initially, at 60°C, the lattice structure thins due to the collapse of the octahedral sheets; at 80°C, the lattice disintegrates and reorganizes into a loose framework akin to albite; and by 100°C, it further reorganizes into a denser framework resembling analcime. The adsorption properties of bentonite exhibit a peak inflection point at 80°C, where the dissolution of the smectite lattice eliminates interlayer pores and exposes numerous polar or negatively charged sites which results in a decrease in specific surface area and an increase in cation exchange capacity and adsorption capacity of Eu3+. This research provides insights into the intricate evolution of bentonite minerals and the associated changes in radionuclide adsorption capacity, contributing to a better understanding of the stability of bentonite barriers and the effective long-term containment of nuclear waste.